diff --git a/ChangeLog b/ChangeLog
index 9c7c6075a7..97e7176f1c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Aug  2 13:23:08 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* configure.in (AC_PROG_CC): AC_PROG_CC tries clang at first on
+	  darwin. [Bug #6816]
+
 Thu Aug  2 11:39:25 2012  Narihiro Nakamura  <authornari@gmail.com>
 
 	* gc.c: return true or false. Patch by Dirkjan Bussink. [Bug #6821]
diff --git a/configure.in b/configure.in
index 27aed2f2ab..fad36e09d9 100644
--- a/configure.in
+++ b/configure.in
@@ -373,7 +373,9 @@ if test x"${build}" != x"${host}"; then
   AC_CHECK_TOOL(CC, gcc)
 fi
 RUBY_MINGW32
-AC_PROG_CC
+AS_CASE(["$build_os"],
+[darwin*], [ AC_PROG_CC(clang gcc cc) ],
+           [ AC_PROG_CC ])
 AC_PROG_CXX
 AC_PROG_GCC_TRADITIONAL
 AC_SUBST(GCC)